The new technology of BiCMOS which utilizes both bipolar and CMOS transistors in a single device has been explored increasingly in the past few years. The advantage of BiCMOS circuits over conventional CMOS or bipolar circuits is that the high speed characteristic of bipolar circuits can be obtained with an integration density and a low power consumption characteristic of CMOS circuits.
BiCMOS buffers, inverters, and gates are known in the art. However, the BiCMOS technology has not been commonly applied to multiplexers or to logic gates having structures similar to multiplexers.
As an example of prior art logic gates, see Best, U.S. Pat. No. 4,417,314, which discloses a CMOS logic circuit that provides AND, OR, XOR, and XNOR outputs. Also see Adair, PCT Patent Publication W086/07173, which discloses a full adder circuit comprised of simple two-input gates and a pair of CMOS pass transistor multiplexers. Neither disclosure utilizes BiCMOS technology. Also, neither disclosure utilizes a differential input or provides a differential output.